Sound signal device



y 1960 E. w. GOSSWILLER 2,946,995

SOUND SIGNAL DEVICE Filed July 8. 1959 2 Sheets-Sheet 1 I I I I "Ii/HIT"22-7 132 2d oasmZZer fizz/9722157 1950 E. w. GOSSWILLER 2,946,995

SOUND srcm. DEVICE Filed July 8, 1959 2 Sheets-Sheet 2 Z::/9.J Z3

United States Patent SOUND SIGNAL DEVICE Earl W. Gosswiller, Chicago,111., assignor to Federal Sign and Signal Corporation, Chicago, Ill., acorporation of New York Filed July 8, 1959, Ser. No. 825,766

6 Claims. c1. s4o 3ss This invention relates to improvements in a soundsignal device of the vibratory type wherein an electromagnet acts withan armature carried by a diaphragm to vibrate the diaphragm and producea sound signal.

Sound signal devices of the vibratory type are well known. It is alsowell known that if, in the operation of a device of this type, thesurface of the pole piece does not conform with or register parallelwith the surface of the armature, ineflicient operation takes place andthe sound produced is of a raucous and unpleasant character.

However, to bring about this conforming relationship has proven to bemost difficult in production and in most instances requires the talentsof a skilled artisan. .For the ordinary user who may be required to tunethe signal after it may have become detuned in service, it issubstantially an impossible task.

The present invention is directed to a sound signal device of thevibratory type wherein the pole piece or pole pieces are so supportedrelative to the armature that they can be made to readily andsubstantially automatically conform with the surface of the armature,the support also being such that by the simple manipulation of a screwthe tone not only can be rendered pleasant and musical, but the volumecan be readily changed.

Another advantage of the present invention resides in a sound signaldevice of the class described which for a predetermined volume and powerconsumption can be made smaller and more compact than has been feasibleheretofore.

Other objects, advantages and features of the present invention will beapparent from the accompanying drawings and following detaileddescription.

In the drawings,

Fig. 1 is a top plan view of a sound signal device embodying thefeatures of the present invention.

Fig. 2 is a sectional view taken on line 22 of Fig. 1.

Fig. 3 is an enlarged sectional view taken on line 3-3 of Fig. 1.

Fig. 4 is a similar sectional view taken on line 4-4 of Fig. 1.

Fig. 5 is an enlarged transverse sectional view taken on line 5-5 ofFig. 1.

Fig. 6 is a detailed skeleton perspective view of the support for thepole pieces.

Referring in detail to the drawings, 1 indicates a relatively rigidrectangular frame constructed of metal which is adapted to be positionedin a casing 3. The casing 3 is also rectangular and a face of the casingis provided with cross-members 4 to form a grill. A diaphragm- 5, ofrelatively thin metal, is also carried within the casing and itsmarginal edge portions are confined between a shoulder 6, formed on theinterior of the casing, and the marginal port-ion of frame 1, theassembly being secured together by screws 7. A gasket 8 may be disposedbetween the marginal portion of the diaphragm 5 and the shoulder 6. Theframe 1 and casing 3 are provided with screw holes 2 for the receptionof screws (not shown) whereby the assembly may be mounted upon asuitable support.

On the front face of diaphragm 5, that is, the face thereof facing thegrill, a secondary vibrating member or amplifier disc 9 is secured bymeans of bolt 10 which extends through both the central portions of thediaphragm 5 and the disc 9. The disc 9 is spaced from the diaphragm by awasher 11 which is also carried by the bolt. On the opposite side of thediaphragm-5 and also carried by bolt 10 is an armature 12, said armaturebeing spaced from the diaphragm by washer 13. The construction hereindescribed is conventional and per se does not constitute the presentinvention.

The armature 12 is disposed substantially centrally of the diaphragm andcompletely includes the projected areas of pole pieces 14 carried by acore 15 which is associated with a solenoid coil 16 circumscribing onepole 17 of the core 15. The core 15 comprises a plurality of iron lamina18 each of which is substantially U-shaped and when said lamina aredisposed in plane-parallel relationship, the core 15 is formed havingleg or pole 17 which carries coil 16 and a spaced leg or pole 19.

Frame 1 carries two spaced lugs 20 which may conveniently be formedintegral with the frame. At the opposite side of the frame a boss 21,preferably formed integral with the frame, is carried. An adjustingscrew 22 having a hexagonally recessed head 23 is loosely positionedthrough an aperture 24 in boss 21, the end portion of said screw beingthreaded to receive elastic stop nut 25. A bridge support 26, at oneend, is provided with an aperture 26 through which the shank of screw 22also extends. A relatively stiff coil spring 27 embraces the shank ofscrew 22 and is confined between the apertured end of the bridge support26 and boss 21.

The opposite end portion of the bridge support is provided with anaperture 28, the end of the bridge support being positioned between lugs20 and being pivotally secured to said lugs by bolt 29. Thus, the bridgesupport may be swung about bolt 29 as a pivot, by manipulating screw 22,spring 27 resiliently assisting or resisting such swinging action.

Each of the lamina 18 comprising core 15 is provided with an aperture 30at the juncture of those legs of the lamina which form pole 19 with thecross-portions of the lamina. Similarly, each lamina is provided with anaperture 31 at the juncture of those legs of the lamina which form pole17 with the cross-portion of the lamina.

The central portion of the bridge support 26 conforms substantially inshape with the lamina 18, that is, the support carries a leg 32 whichconforms substantially with the legs of the lamina which form pole 17,and a portion 33 of the bridge extends downwardly and conformssubstantially with the legs of the lamina which form pole 19.

The bridge support 26 is provided with an aperture 34 which, when thedevice is assembled, is in axial alignment with apertures 31 in thelamina. As a feature of the invention, the bridge support 26 is providedwith a relatively enlarged aperture 35 which, when the device isassembled, is in substantially axial alignment with the apertures 30 inthe lamina.

The core 15 is composed of a plurality of lamina which are divided intotwo groups, of an equal number of lamina, one of said groups beingdisposed on each side of said bridge support. A bolt 36 extends throughthe apertures '31 of the lamina of each group and also extends throughaperture 34 in the bridge support, and a second bolt 37 extends throughapertures 30 of the two groups of lamina and through aperture 35 in thebridge support. Elastic stop nuts 38 engage the ends of the bolts 36 and37 and spring washers 38 are confined adjacent the heads of the screwswhereby a desired degree The arrangement is suchlthat when the device isassembled and the core 15 is carried'by the'bridgeisupy port, the polepieces 14 will be disposed adjacent the armature 12. When assemblingthe'core and bridge support the nuts 38 are initially turned down untilthe lamina are tightly assembled in fac'e-to-face relationship and thenthe nuts are backed ofi? a slight degree whereby the spring washers 38'resiliently permit relativeplzineparallel motion of the lamina and theincluded bridge:

support by the exertion of a substantial degree of force. The apertures30 and 31 are sufliciently oversize relative to the diameter ofthe-bolts 37 and 36', respectively' so as to permit a degree of relativeface-to-facemovefnent of the lamina with respect to each other. Inaddition, because of the relatively large size of the aperture 35' withend which is supported by said bridge support adjacent said armature,said core comprising a plurality of ferromagnetic lamina, said bridgesupport being provided with an aperture, said lamina being provided withapertures, a bolt extending through the apertures in said lamina andthrough the aperture in said bridge support frictionally to hold theremnant face-to-face relationship with eachother and with the bridgesupport, the

respect to bolt 37, a degree of rocking movement of the core 15 as awhole about bolt 36 is provided.

Thus, the lamina 18 may move in plane-parallelree lationship to eachother; the core as a whole independent of the bridge support may rockabout bolt 36, and the entire assembly including the core andbridge'suppo'rt may be rocked about bolt 29 as an axis. Inasmuch asit isdesirable that the end area of each lamina constituting the pole pieces14 conform with the surface of the arma-.

ture, the freedom of movement of the lamina themselves,

the core as a Whole and the core and the bridge respect to each other,brings this optimum condition about. t

In practice, screw 22 maybe so manipulated as to bring the pole piecesinto contact with the surface of the armature when the diaphragm 5 isunfiexed. Of course;

when the coil 16 is energized, no sound'will be produced.

While the coil is energized, screw 22 may be backed off to space thepole pieces from the armature. Of course,

pieces, the components of the core, including the core.

itself, will become properly positioned to cause the end areas of eachof the lamina to conformwith the surface.

of the armature.

This conforming action takes place substantially auto-.

matically within a wide working range of spacing of the pole pieces fromthe armature. Thus, the volume of the signal may be changed by themanipulation of screw 22 and the musical quality of the tone will alwaysbeas sured at desired variations in volume.

Although the bridge support 26 is shown anddescribed as being swingablymounted upon the frame and is supported at one end on spring 27, thebenefits of the invention are inherent in a bridge support which may berigidly mounted upon the frame or adjustably mounted at bothends uponsprings, such as, spring 27.

The device specifically illustrated in the drawings is intended tooperate on alternating current. It is to be understood, however, byconventional circuitry the device can also be used with direct current.Other modifications of the invention which do not depart from the spiritof the invention will be apparentto anyone skilled in the art, and,hence, it is not intended that the invention be limited to the exactdetails shown and described except as necessitated by the appendedclaims.

I claim as my invention:

1. A sound signal device comprising, a frame, a resilient diaphragmcarried on said frame for vibrating movement, said diaphragm includingan armature, a bridge support carried by said frame and extending acrosssaid diaphragm in spaced relationship thereto, an electromagneticassembly carried by said bridge support, said assembly comprising aferromagnetic core carrying an actuating coil, said core comprising apole face at one' However, because of the various degrees ofv diameterof the aperture in said bridge'support being sufficiently greater thanthe diameter of said bolt to permit relative face-to-face movement ofsome of said lamina with respect to said bridge support.

2. A sound signal device'comprising, a frame, a resilient diaphragmcarried on said frame for vibrating movement, said diaphragm includingan armature, a bridge support carried by said frame and extending acrosssaid diaphragm in spaced relationship thereto, an electromagneticassembly carried by said bridge support, said assembly comprising aferromagnetic core carrying an actuating coil, said core comprising apole face at one end which is supported by said bridge support adjacentsaid armature, said core comprising a plurality of ferromagnetic lamina,said bridge support being provided with a pair of spaced apertures, saidlamina being provided with correspondingly spaced apertures, a boltextending through each bridge support aperture and the correspondinglamina apertures frictionally to hold the lamina in face-to-facerelationship with each other and with said bridge support, the diameterof one of the apertures in said bridge support being sufficientlygreater than the diameter of the bolt through said aperture to permitrelative face-to-face movement of some of said lamina with respect tosaid bridge support and to permit limited rotary movement of said laminaabout the bolt in the other aperture of the bridge support.

3. A sound signal device comprising, a frame, a resilient diaphragmcarried on said frame for vibrating movement, said diaphragm includingan armature, a bridge support carried by said frame and extending acrosssaid diaphragm in spaced relationship thereto, an electromagneticassembly car'ried by said bridge support, said assembly comprising aferromagnetic core carrying an actuating coil, said core comprising apole face at one end which is supported by said bridge support adjacentsaid armature, said core comprising a plurality offerromagnetic lamina,said bridge support being provided with a pair of spaced apertures, eachof said laminae being provided with correspondingly spaced apertures, abolt extending through each bridge support aperture and through thecorresponding apertures in the lamina frictionally to hold the lamina inface-to-face relationship with each other and with the bridge support,the diameter of one of the apertures in said bridge support beingsufficiently greater than the bolt through said enlarged aperture topermit limited rotating movement of the lamina about the bolt in .theother bridge support aperture, and the diameter of the laminaaperturesbeing'sufiiciently greater than the diameters of the boltstherethrough to permit limited face-to-face movement of the lamina withrespect to each other.

4. A sound signal device comprising, a frame, a resilient diaphragmcarried on said frame for vibrating movement, said diaphragm includingan armature, a bridge support, an electromagnetic assembly carried bysaid bridge support, said assembly comprising a magnetic core carryingan actuating coil, said core comprising a pole face at one end-meanscarriedby saidframe pivotally engaging one end' of said bridge support,resilient means carried by said frame spaced across said diaphragm fromsaid pivotal engaging means resiliently supporting the opposite end ofsaidbridge support'to dispose the an aperture, and said lamina beingprovided with apervim tures, a bolt extending through the apertures insaid lamina and through the aperture in said bridge support to hold saidlamina in face-to-face relationship with each other and with said bridgesupport, the diameter of the aperture in said bridge support beingsufficiently greater than the diameter of said bolt to permit relativeface-toface movement of some of said lamina with respect to said bridgesupport, and means carried by said frame and bridge support for movingthe resiliently supported end of the bridge support about the pivotallyconnected end thereof.

5. A sound signal device comprising, a frame, a resilient diaphragmcarried on said frame for vibrating movement, said diaphragm includingan armature, a bridge support, an electromagnetic assembly carried bysaid bridge support, said assembly comprising a magnetic core carryingan actuating coil, said core comprising a pole face at one end, meanscarried by said frame pivotally engaging one end of said bridge support,resilient means carried by said frame spaced across said diaphragm fromsaid pivotal engaging means resiliently supporting the opposite end ofsaid bridge support to dispose the pole face of the core at apredetermined position adjacent said armature, said core comprising aplurality of ferromagnetic lamina, said bridge support being providedwith a pair of spaced apertures, said lamina being provided withcorrespondingly spaced apertures, a bolt extending through each bridgesupport aperture and the corresponding lamina apertures to hold thelamina in face-to-face relationship with each other and with said bridgesupport, the diameter of one of the apertures in said bridge supportbeing suificiently greater than the diameter of the bolt through saidaperture to permit relative facetoface movement of some of said laminawith respect to said bridge support and to permit limited rotarymovement of said lamina about the bolt in the other aperture of thebridge support.

6. A sound signal device comprising, a frame, a resilient diaphragmcarried on said frame for vibrating movement, said diaphragm includingan armature, a bridge support, an electromagnetic assembly carried bysaid bridge support, said assembly comprising a magnetic core carryingan actuating coil, said core comprising a pole face at one end, meanscarried by said frame pivotal- -ly engaging one end of said bridgesupport, resilient means carried by said frame spaced across saiddiaphragm from said pivotal engaging means resiliently supporting theopposite end of said bridge support to dispose the pole face of the coreat a predetermined position adjacent said armature, said core comprisinga plurality of ferromagnetic lamina, said bridge support being providedwith an aperture, and said lamina being provided with apertures, a boltextending through the apertures in said lamina and through the aperturein said bridge support to hold said lamina in face-to-face relationshipwith each other and with said bridge support on each side of said bridgesupport whereby said bridge support is disposed substantially centrallyof said lamina, the diameter of the aperture in said bridge supportbeing sutliciently greater than the diameter of said bolt to permitface-to-face movement of some of said lamina with respect to said bridgesupport, and means carried by said frame and bridge support for movingthe resiliently supported end of the bridge support about the pivotallyconnected end thereof.

No references cited.

